In a distributed network of networked devices supporting nondisruptive upgrades requires that each device comprising the distributed network of networked devices running different versions of a software package or a software product communicate in compatible versions of network protocol, and restrict globally viewable persistent on-disk states to those that can be correctly parsed and handled by all devices in the network of networked devices. Implementing such logic typically requires that each device be able to determine what features are supported by other devices in the distributed network.